1. Field of the Invention
The present invention relates to computer system cooling, particularly in the context of a rear-door heat exchanger.
2. Background of the Related Art
Computer systems use electrical energy and produce heat as a byproduct. Rack-based computer systems include many rack-mounted components in a high-density arrangement, which can produce a considerable amount of heat. Heat must be removed from the rack to control internal temperatures and to maintain system reliability, performance, and longevity. In a conventional rack-based computer system, rack-mounted fans move cool air through the rack to remove the heat and cool the components. The heated exhaust air is then transported to a computer-room air conditioner (“CRAC”), which cools the air before returning the cooled air to the data center. Energy efficiency in a datacenter dramatically affects the total cost of ownership of datacenter equipment.
A rear-door heat exchanger (RDHX) is a particular type of cooling system provided on a rack. An RDHX is mounted on the rear of the rack and provides an air-to-liquid heat exchanger that circulates coolant through a fin tube assembly. Airflow exiting the rack is passed through the RDHX, which transfers heat from the airflow to the fin tube assembly. The RDHX may be opened like a door to access the rear of the rack. RDHX systems have proven to be more efficient than conventional CRAC units at cooling rack-based computer systems. Some RDHX systems developed by IBM can remove one-hundred percent or more of the heat added by the computer system to the airflow through the rack, eliminating the need for a conventional CRAC.